JPH04118117U - honeycomb filter - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a honeycomb filter for an exhaust gas purification device that has excellent thermal shock resistance. [Structure] Thermal shock resistance is improved by providing a reinforcing member on the outer periphery of a honeycomb filter for an exhaust gas purification device of an internal combustion engine made of a porous sintered body to improve mechanical strength.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to honeycomb filters used in exhaust gas purification devices for internal combustion engines. It is something.

0002

[Conventional technology]

In general, filters made of porous sintered bodies formed in a honeycomb shape are used for exhaust gas in internal combustion engines. Used in equipment to remove soot mixed in air gas. This type of filter is By being connected to the exhaust side, it collects soot contained in exhaust gas. captured in the filter. The collected soot is burned by heating it with a burner or heater, and the filter returns to its original state. It will be regenerated to the state of .

0003

[Problem that the idea aims to solve]

When the above honeycomb filter is regenerated, generally only a portion of the filter is regenerated. Often partially heated. Therefore, the temperature distribution in each part of the filter becomes uneven. This temperature difference easily generates stress in the filter in the axial or circumferential direction. do. It is also known that this stress increases as the size of the filter increases. If the stress exceeds the mechanical strength of the filter, cracks will occur in the filter. , the filter will be damaged.

0004 However, the material used in honeycomb filters is mechanically weak enough to withstand relatively small stresses. Because it is a porous sintered body that only has physical strength, it can be used for a long period of time. It is difficult to form large filters that do not easily generate scratches or cracks. be. This invention was made in view of the above problems, and its purpose is to improve the filter By improving mechanical strength, filters can be made larger than before, and cracks are less likely to occur. We offer a honeycomb filter that can be used for a long time and prevents damage caused by raw materials. It is about providing.

[0005]

[Means to solve the problem]

In order to achieve the above purpose, the present invention has developed a casing that communicates with the exhaust side of an internal combustion engine. In the honeycomb filter disposed within the honeycomb filter, the honeycomb filter is made of porous sintered material. It is formed by a body, and a reinforcing member is provided on its outer periphery.

[0006]

[Effect]

By reinforcing the filter from the outer periphery, which is made only of porous sintered material, mechanical strength is imparted to the filter. Therefore, by heat treatment, each part of the filter Suppose that the temperature distribution becomes non-uniform and the stress in the longitudinal or circumferential direction increases. However, the filter can withstand the stress and is less likely to crack.

[0007] The reinforcing member may be, for example, a solid sintered body with high density and no pores. It is desirable that The reason is that it has higher strength than a porous sintered body. Also, it is desirable that the reinforcing member has the same composition as the main body of the honeycomb filter. . This is because it can be integrally molded. When the reinforcing member is arranged along the longitudinal direction of the honeycomb filter, its width It is desirable that the height is 5 to 20 mm and the height is 2 to 10 mm. The reason is width and height. If the temperature is larger than these values, temperature differences will easily occur and thermal shock resistance will decrease. This is because if the value is smaller than these values, a sufficient reinforcing effect cannot be obtained. In addition, the front It is particularly advantageous if the marking width is 10 mm and the height is 5 mm; The member resists the stress caused by the temperature difference between the inflow and outflow sides of the filter in the circumferential direction. can effectively prevent cracks from occurring.

[0008] In addition, when this reinforcing member is arranged along the circumferential direction of the honeycomb filter, It is preferable that the width is 10 to 25 mm and the height is 2 to 10 mm. The reason is, If the width and height are larger than these values, temperature differences will easily occur and thermal shock resistance will decrease. This is because if the value is smaller than these values, a sufficient reinforcing effect cannot be obtained. . Furthermore, it is particularly advantageous that the width is 15 mm and the height is 5 mm; For example, the reinforcing member resists the stress caused by the temperature difference between the center and the outer circumference of the filter. The generation of cracks in the radial direction can be effectively prevented.

[0009]

【Example】

The honeycomb filter of this invention is used as an exhaust gas purification device for diesel engines. A concrete first embodiment will be described with reference to the drawings. As shown in FIG. 1, in the first embodiment, the exhaust gas purification device 1 is made of a metal pipe case. casing 2, a passage 2a of the casing 2 is in contact with an exhaust pipe Ea of an internal combustion engine E. It is continued. Inside this casing 2, there is a A honeycomb filter 3 is provided for the purpose of Also, honeycomb filter 3 A burner 4 for regeneration processing is provided on the gas inflow side.

As shown in FIG. 2, the honeycomb filter 3 of the first embodiment is formed into a honeycomb shape using a porous sintered body, for example, a silicon carbide sintered body, and has a cylindrical shape (larger than a normal size filter). It has a length of 250 mm and a diameter of 140 mm. A plurality of communication holes 5 are formed in the axial direction of the filter 3 . A sealing piece 6 made of a porous sintered body and having a thickness of 5 mm is disposed at either end of the exhaust gas inflow side or the exhaust gas outflow side of each communication hole 5. This sealing piece 6 forms cells 7a and 7b that open on either the inflow side or the outflow side. In addition, in this filter 3, the number of cells 7a, 7b is 170/ ^inch2 , the wall thickness, which is the width between cells 7a, 7b, is 0.43 mm, and the outer wall thickness of cells 7a, 7b in the outermost layer portion is 0. It is .5mm.

[0011] The inner walls of the cells 7a and 7b of the honeycomb filter 3 are coated with platinum group elements and other metals. An oxidation catalyst consisting of metal elements and their oxides is supported. Therefore, as shown in Figure 2. The exhaust gas introduced into the cell 7a side, which opens on the inflow side, flows through each cell 7a, 7. It is discharged to the adjacent cell 7b side which opens on the outflow side through the inner wall 8 located between Ru. At this time, only the soot is trapped on the eight inner walls of the cells 7a and 7b, and the exhaust gas is removed. Gas purification takes place. When a predetermined amount of soot is trapped in the filter 3, the burner 4 is ignited, and heating of the honeycomb filter 3 is started. And honeycomb fill The soot in the filter 3 is burned, and the honeycomb filter 3 is regenerated to its original state.

0012 As shown in FIG. 3(a), a plurality of ( In the first embodiment, 16 reinforcing members 9 are bonded at equal intervals. These reinforcements For member 9, a solid silicon carbide sintered body is used. Also, shown in Figure 3(b) The width W1 of these reinforcing members 9 is set to 10 mm, and the height L1 is set to 5 mm. The boundary between the side surface of the reinforcing member 9 and the outer peripheral surface of the filter 3 has a radius of 2 mm. A rounded portion R is provided. Note that the reinforcing member 9 is formed by extrusion molding. It is possible to form it integrally with the tab 3.

[0013] The honeycomb filter 10 of the second embodiment is made of silicon carbide sintered body as in the first embodiment. Therefore, it is formed into a honeycomb shape and has a cylindrical shape with a length of 250 mm and a diameter of 140 mm. ing. Similarly, a plurality of cells 7a and 7b are formed in the axial direction of the filter 10. The soot trapped by the cells 7a and 7b is transferred to the burner 4 described above. It is regenerated by heat treatment.

[0014] As shown in FIG. 4(a), on the outer peripheral surface of the honeycomb filter 10 of the second embodiment, Two reinforcing members 11 extending in the circumferential direction are bonded. These reinforcing members 11 are respectively 50 mm from the inlet end of the filter 10 and 50 mm from the outflow end of the filter 10. It is glued at the 0mm position. In addition, the reinforcing member 11 is fully equipped as in the first embodiment. A sintered silicon carbide body is used. These reinforcements, as shown in Figure 4(b) The width W2 of member 11 is set to 15 mm, and the height H2 is set to 5 mm. A rounded part R with a radius of 2 mm is formed at the boundary between the side surface of the member 11 and the outer peripheral surface of the filter 10. is provided.

[0015] Furthermore, to explain the honeycomb filter 12 of the third embodiment, this filter 12 is also made of the same material and has the same size as the first and second embodiments, and similarly, the cell 7a , 7b are formed. Outer peripheral surface of honeycomb filter 12 of this embodiment A reinforcing member 13 having a thickness of 3 mm as shown in FIG. 5 is bonded to the entire structure. In addition, supplementary The strong member 13 is a solid silicon carbide sintered body, and the filter 12 is formed by extrusion molding. It is possible to form it integrally with.

[0016] And the honeycomb filter in the first to third embodiments configured as above 3, 10, 12, and the same material and size as the filters 3, 10, 12. Heat treatment was performed on a conventional honeycomb filter (comparative example) that does not have reinforcing members. The mechanical strength of each filter was compared. Heat treatment with burner 4 is 700℃ The test was repeated for 10 minutes, and the state of crack generation was observed each time. .

[0017] As a result, in the honeycomb filters 3, 10, 12 of the first to third embodiments, the heat treatment No cracks were observed even after repeating the process 10 times. However, comparison In the example honeycomb filter, cracks occur in the axial and circumferential directions, causing the filter to crack. It was found that the tassel was damaged. As is clear from the above results, such differences occur between each example and the comparative example. The difference is related to the presence or absence of the reinforcing members 9, 11, and 13. That is, the porous sintered body The filters 3, 10, 12 formed by The filters 3, 10, and 12 are reinforced with mechanical strength greater than that of conventional filters. It is. Therefore, even if stress increases due to heat treatment, filters 3 and 1 0,12 can withstand that stress and without cracking. It becomes possible to use it for a long period of time. In addition, these reinforcing members 9, 11, 13 are installed. The overall size of the filters 3, 10, and 12 can be increased by It has a length of 500 mm and an outer diameter of 500 mm.

[0018] Note that the present invention is not limited to the above embodiments, and does not depart from the scope of the invention. It is possible to change the following aspects within the scope. for example, (a) A first embodiment in which the reinforcing member 9 is formed only in the longitudinal direction, or a reinforcing member 9 in the circumferential direction. Instead of the second embodiment in which the reinforcing member 11 is formed only in the filter, as shown in FIG. Reinforcing members 9 and 11 may be provided along both directions of 14. (b) Instead of the reinforcing member 13 of the third embodiment, a filter 15 shown in FIG. Alternatively, the reinforcing member 16 may be formed in a partially arcuate cross-section with respect to the outer circumferential portion. same As shown in FIG. 7, in place of the reinforcing members 9 and 11 of the first and second embodiments, a filter The reinforcing member 17 may be formed inside the outer peripheral portion of the tab 15.

[0019]

[Effect of the idea]

According to the honeycomb filter of the present invention, the mechanical strength of the filter has been improved. , it can be made larger than before, and damage caused by cracks can be prevented. It has excellent effects and can be used for a long period of time.

[Brief explanation of drawings]

FIG. 1 is a partial front cross-sectional view showing a state in which a honeycomb filter is installed in a first embodiment embodying the invention.

FIG. 2 is an enlarged sectional view of the honeycomb filter in the first embodiment.

FIG. 3(a) is an enlarged front view of the honeycomb filter in the first embodiment, and FIG. 3(b) is a partially enlarged cross-sectional view of its reinforcing member.

FIG. 4(a) is an enlarged front view of a honeycomb filter in a second embodiment, and FIG. 4(b) is a partially enlarged sectional view of a reinforcing member thereof.

FIG. 5 is an enlarged front view of a honeycomb filter in a third embodiment.

FIG. 6 is an enlarged front view of a honeycomb filter in another example.

FIG. 7 is an enlarged side view showing a reinforcing member of the honeycomb filter.

[Explanation of symbols]

2 casing, 3, 10, 12 honeycomb filter,
4 Burner, 9, 11, 13 Reinforcing member, E Internal combustion engine, W1, W2 Width of reinforcing member, H1, H2 Height of reinforcing member.

Claims (4)

[Scope of utility model registration request] Claim 1: A honeycomb filter (3, 1) arranged in a casing (2) communicating with the exhaust side of an internal combustion engine (E).
0,12), the honeycomb filter (3,1
0, 12) is formed of a porous sintered body, and a reinforcing member (9, 11, 13) is provided on the outer periphery of the honeycomb filter. 2. The honeycomb filter according to claim 1, wherein the reinforcing member (9, 11, 13) is a solid sintered body. 3. The reinforcing member (9) is arranged along the longitudinal direction of the honeycomb filter (3), and has a width (W1) of 5 to 20 mm and a height (H1) of 2 to 10 mm. The honeycomb filter according to claim 2, characterized in that: 4. The reinforcing member (11) is disposed along the circumferential direction of the honeycomb filter (10), and has a width (W2
) is 10 to 25 mm, and the height (H2) is 2 to 10 mm.